• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.2
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• pp.29-38
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• 2010

Network Video Recorder becomes popular as a next generation surveillance system connecting all cameras and video server in network environment because it can provide ease of installation and efficient management and maintenance. But in case of data damage, the storage device in traditional NVR has no recovery scheme and it is disabled in processing real-time requests. In this paper, we propose an Reliable Storage using Parity and Mirroring scheme for improving reliability on storage device and maintaining system on realtime. RSPM uses a Liberation coding to recover damaged multimedia data and dynamic mirroring to repair corrupted system data and to maintain real-time operation. RSPM using the Liberation code is 11.29% lesser than traditional file system and 5.21% less than RSPM using parity code in terms of loss rate of damaged multimedia data.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.273-278
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• 2014

Recent use of electricity during peak hours electricity supply-demand imbalance is inevitable that limit power use force. Therefore, in this paper, a circuit of parallel power operation equipment for peak power reduction which saves the power to electricity storage device during the non-peak power time and supply from the storage power during the expected power shortages time is designed Through this circuitry, the peak power of the commercial power supply with the parallel operation and connection of the commercial power supply and the power supply of the inverter from electricity storage that is a key feature of PRS(Peak power Reduction System) can be controlled. In addition, in order to increase the efficiency, a Transless Power Circuit DC-AC inverter is developed. Moreover, a variable impedance control is applied to the storage of electric power of an Uninterruptible Power Supply associated with a commercial power source.

• Transactions of the Society of Information Storage Systems
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• v.3 no.1
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• pp.1-4
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• 2007

A high density optical data storage device has been required for many years. In the field of the optical data storage, a near-field recording (NFR) technology is considered as a next generation one for achieving the high data density. Due to an evanescent wave effect occurred under 100nm distance which is the excessively small distance between the SIL and the disc, the most significant and difficult problem in this technology is to maintain a gap between a solid immersion lens (SIL) and a disc. Also, maintaining the gap under at least 50nm is required in the NFR gap servo system to use the evanescent wave effect efficiently. There are some institutes that have shown the novel gap servo control. In general, they use a mode switching servo method which consists of approach, hand-over and gap control mode. However there is a critical problem such as an overshoot at the tuning point from the approach mode to the hand-over mode, which may cause a collision between the SIL and the disc. In this paper, we show our NFR system and an improved gap servo system using an exponential function as the approach mode which can reduce the overshoot.

• Transactions of the Society of Information Storage Systems
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• v.6 no.2
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• pp.79-82
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• 2010

In optical imaging systems, such as microscopes, high resolution exposure systems, and optical storage devices, higher optical resolution is a requirement. One of the promising technologies that is able to satisfy this requirement with relatively simple construction and reliable performance are, solid immersion lens (SIL)-based near-field (NF) optical systems. High NA optical systems using annular apertures have been investigated as one solution to achieve higher resolutions and an extended focal depth. By applying an optimized annular aperture to convention SIL optical head resolution can be increased by approximately 20%. This novel SIL-based near-field optics will be verified through experiments such as measuring focused beam spot profiles and observing the topology of a measurement sample. The studied SIL-based near-field optics can be applicable to not only next generation optical storage device but also high resolution microscopy and pattering technologies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.381-385
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• 2010

An aging Society solitary life old mans are increasing. The nurses have to visit old mans and must confirm their disease, because they do not act well. It is very difficult to take care old man, because the number of Nurses are small. This problem is solved by collection of data about condition of old mans from long distance. Data communication with Ethernet have benefit to collection of measurement of old man's condition. The Data storage system an long distance place are storaged data and after several day data was transmitted to the DB over the Ethernet. For Miniaturization of such system the system must be OS-less Embedded Ethernet Server system. Such system manages the file management system only with H/W. The Storage device is used SD-card. SD Card is small size and operates with small power. By using 512MB sd memory card, it is possible to storage during 5~6 years, 10 byte of temperature value per second. In this paper, we make a Embedded Ethernet Server using W3100A, Atmega128 MCU and data stroage device using SD-Card. This system operates with O/S-less Embedded Ethernet Server. We talk about file System, Storage and Ethernet. We explained about MCU Atmega128, Interface between LAN LSIand W3100A, Interface between W3100A and Phyceiver RTL8201, data I/O between MCU and SD-Card and File System. We shows the experiment device and result of monitoring.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.94-102
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• 2016

Recently, the I/O performance of a single node is rapidly improving due to the advent of high-performance SSD. As a result, the next-generation storage platform based on SSD has received a great deal of attention and such storage platforms are increasingly adopted to commodity servers or data centers that look for the high-bandwidth computation and I/O. However, building all SSD-based storage platform may not be cost-effective because the price per storage capacity is very high as compared to that of HDD. In this paper. we propose a hybrid file management solution, called HyPLVM(Hybrid Priority Logical Volume Manager), which combines the strength of SSD with the desirable aspects of low-price, high-storage capacity HDD. HyPLVM prioritizes the files and directories to be accessed by users, in order to determine the target storage device (SSD/HDD) in which files are allocated, while mitigating the cost of building storage platforms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.324-327
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• 2013

Recently, due to evolving cloud computing technology, we can easily and transparently utilize both local computing resource and remote computing resource in real life. Especially, enhancing smart device technologies and network infrastructures promote an increase of needs to share files between local smart devices and cloud storages. However, since smart devices have a limited storage space, storing files on cloud storage causes a starvation problem of local storage. It means that users can face a storage-lack problem even a cloud storage service provide a huge file storing space. In this research, we propose a method to manage files between smart devices and cloud storages. Our approach calculate file usage pattern based on recently used date, and then this approach determines local files being migrated. As a result, our approach is sufficient for handling data synchronization between big data storage farm and local thin client which contains limited storage space.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.267-276
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• 2009

Nowadays, numerous of valuable internet services are available not only for personal computer but also for mobile appliances in wireless network environment. Therefore, as the amount of contents is increased for those services, the storage limitation on mobile devices has became a significant issue. In this paper, we present a new block-level storage network protocol, iATA (Internet Advanced Technology Attachment) as a solution to the above problem. iATA is designed to transport ATA block-level data and command over the ubiquitous TCP/IP network. With iATA, a mobile appliance is able to access and control the ATA storage devices natively through network from anywhere and at anytime as if the storage devices is attached locally. We describe the concepts, design and diverse consideration of iATA protocol. Based on the benchmark experiments and application exploitation, we strongly believe that iATA as a light-weight protocol is efficient and cost-effective to be used as a storage network protocol on a resource limited device that utilizes common-off-the-shelf storage hardware and existing IP infrastructure.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.228-230
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• 2020

The emergence of collaborative learning to the public is to tackle the user's privacy issue in centralized learning by bringing the AI models to the data source or client device for training Collaborative learning employs computing and storage resources on the client's device. Thus, it is privacy preserved by design. In harmony, blockchain is also prominent since it does not require an intermediary to process a transaction. However, these approaches are not yet fully ripe to be implemented in the real world, especially for the complex system (several challenges need to be addressed). In this work, we present the performance of collaborative learning and potential use case of blockchain. Further, we discuss privacy issues in the system.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.318-330
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• 2002

This paper discusses the design and implementation of a video server which uses tertiary device, such as magneto-optical jukebox or tape library, as a source of media archiving. In order to handle the tertiary device in the framework of disk-based stream service model, a sophisticated streaming model is required for server and it should consider the device-specific performance characteristics of tertiary storage. We have carefully designed the streaming mechanism for server whose key functionalities include stream scheduling, disk caching and admission control. The proposed system has been implemented on Windows 2000 platform which is equipped with a magneto-optical jukebox. The design principles of the server are validated with the experiments and the performance characteristics is analyzed.